ProjectSummary Humanpluripotentstemcellderivedendothelialcells(hPSC-ECs)andpericytesareanidealautologouscell sourceforuseinvasculartherapies.ECslinetheinnerlayerofthevasculatureandpericytesprovidesupport tosmalldiametervesselsinordertoregulatevascularpermeability.DerivationofthesecellsfromhPSCs requirestimesensitivedeliveryofgrowthfactorsandsmallmoleculesinordertoinducevascularfate. Characterizationofthesecellsisoftenlimitedto2Dinvitroassaysandcellsurfaceproteinverification.Aswe movetowardstherapeuticuse,functionalcharacterizationisnecessarytoensuretheirtranslationalefficiency andefficacy.HypoxiahasbeenshowntobeakeyregulatorofECfate,neovascularization,andregeneration. However,itsroleinvascularstabilizationthroughpericyterecruitmenthasnotbeenstudied.Here,thorough analysisofhPSC-ECsandpericytesinhypoxicenvironmentsweaimto:(1)StudynetworkkineticsofhPSC- ECsin3Dlowoxygenenvironments,(2)studyhPSC-ECsandhPSC-pericyteinteractionsinhypoxiainvitro, and(3)StudyhPSC-EC-pericyteinteractionsinamouseoxygeninducedretinopathymodel.Theseaims requireamultidisciplinaryapproach,interfacingstemcellandvascularbiologywithtissueengineering. SuccessfulcompletionoftheseaimswillbroadenourunderstandingofhPSC-ECsandpericytesbehavior towardstherapeuticmodalities.